The original question was increasing power from 10W to 20W on a K2 used as an "emergency communication source for serious backcountry trips (multi-day wilderness whitewater rafting, etc.)" That is not very similar to DXing or contesting. In that situation, you get a few dB by throwing your wire over a different tree, trying a different band, trying a different time of day, a different place in the canyon, and so on.
wunder K6WRU On Sep 27, 2013, at 3:40 PM, Jim Brown wrote: > On 9/27/2013 12:37 PM, Vic K2VCO wrote: >> This argument will never die. > > As long as some of those doing the talking are ignorant of the facts, yes. :) > >> I maintain that even ONE dB matters in this situation. > > And you are correct. Here are the FACTS. The 6dB and 10 dB "rules of thumb" > are based on the FACT that a 6-10 dB change in the loudness of a sound that > is well above the background noise level will be perceived by the human > ear/brain as "twice as loud," or half as loud. The key words here are "well > above the background noise level." This fact is quite well known from the > study of psychoacoustics (that is, how humans hear), and is related to the > fact that human hearing and sight are logarithmic in their response to > loudness and brightness. > > The FACTS are very different if the desired "signal" is close to the noise > level, or to the level of other sounds. In that situation, a change as little > as 1-2 dB can be VERY perceptible, and make the difference between hearing > and not hearing it. One of the things I did professionally was mix sound for > live jazz performances. It wasn't long before I learned that changes of only > 2-2 dB in the balance between instruments was often the difference between > just right and not hearing one of them. > > Most serious contesters and DXers fight for every dB in their stations. > Consider that the gain of the BEST 2-el beam over a dipole at the same height > is no more than 3-4 dB, and that adding another element typically adds 1 - > 1.5 dB. And that assumes that these are well designed, efficient antennas. > Those with traps are 1-3 dB less than that. Note that these are MEASURED > numbers, not advertising numbers, and are taken from documentation of an > excellent series of tests of a dozen or so tri-banders by N0AX and K7LXC > about 15 years ago. Ward and Steve actually measured two big antennas with > negative gain as compared to a dipole. :) > > 73, Jim K9YC > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
